I recently started playing Dota 2 again for the first time in many months, and am experiencing a consistent issue whereby after I launch the client, the mouse cursor remains as the default windows cursor rather than changing to the in-game cursor. I am then unable to click on anything on the screen at all. I have to keep relaunching the client over and over and maybe 1 times in 10 will it launch properly and be usable.

I'm running the game in a borderless window, on Windows 7 if that information is relevant at all. Not sure what other information I might need to give.